Pneumatic clamp

The pneumatic clamp comprises an air cylinder, a crank arm connecting plate, a clamping jaw, a clamping arm and a follow-up pressing rod, the clamping jaw comprises multiple sets of crank arms, the air cylinder is fixed to an air cylinder installation base, one end of a connecting rod and the middle points of the crank arms are hinged to the air cylinder installation base, the second points of the crank arms are connected with the crank arm connecting plate, and the crank arm connecting plate is installed below a piston rod of the air cylinder. The first point of the crank arm and the other end of the connecting rod are hinged to the two ends of the upper portion of the clamping arm respectively, and the lower portion of the clamping arm is movably connected with the follow-up pressing rod. The purpose of clamping a workpiece is achieved through the air cylinder and the crank arm structure, synchronous movement of four claws can be achieved through one air cylinder, and the compatible diameter range is wide;